If you have wondered whether you can afford to buy in San Mateo County, you deserve more than “it depends.” Start with a purchase price, a down payment, a realistic monthly budget, and a lender who can compare the options with you.
The short answer
You do not automatically need 20% down. The amount you need depends on the home, loan program, monthly debts, and cash you want to keep after closing. A lower down payment can get you started, but it usually raises the monthly cost.
Start with the type of home and the city
San Mateo County is not one price point. A condo in South San Francisco or Daly City, a townhome in San Bruno, and a detached home in Burlingame can call for very different budgets. Condition, HOA dues, insurance, and property taxes also change the monthly total.
The price examples below are illustrations, not a promise that a particular type of home is available at that price today. I would narrow the search using current listings and recent comparable sales in the neighborhoods you actually want.
How much down payment do you need?
- FHA: A qualified buyer may be able to put 3.5% down. FHA loans carry mortgage insurance and have local loan limits; the 2026 high-cost ceiling for a one-unit FHA loan is $1,249,125.
- Conventional: Some programs allow 3% down for eligible buyers; 5% down is another common starting point. Mortgage insurance, interest rate, and eligibility depend on the specific loan.
- Jumbo: A loan above San Mateo County’s 2026 one-unit conforming limit of $1,249,125 generally requires jumbo financing. Down payment and reserve requirements vary by lender and borrower.
Plan for closing costs and money left in reserve, too. A useful early planning range for closing costs is roughly 2%–3% of the price, but the actual amount depends on the loan, property, taxes, insurance, and negotiated terms. Ask for a written loan estimate before treating any rule of thumb as your number.
What might the monthly payment and income look like?
These four scenarios show how a change in down payment affects the budget. They use a 6.95% illustrative 30-year fixed rate, matching Freddie Mac’s September 17, 2026 national survey average; 1.2% annual property tax; estimated insurance; a $600 monthly HOA for the condo; estimated mortgage insurance when applicable; and $500 in other monthly debt. The income column uses a 43% debt-to-income planning ratio.
| Purchase scenario | Down payment | Estimated monthly housing cost | Illustrative gross household income |
|---|---|---|---|
| $850,000 condo, $600 HOA | 5% · $42,500 | About $7,400 | About $220,000/year |
| $850,000 condo, $600 HOA | 20% · $170,000 | About $6,100 | About $185,000/year |
| $1,500,000 home | 10% · $150,000 | About $11,100 | About $325,000/year |
| $2,150,000 home | 20% · $430,000 | About $14,000 | About $405,000/year |
Illustrations only, not a loan quote or approval. The $1.5 million scenario assumes jumbo financing. Actual rate, mortgage insurance, HOA, tax assessment, homeowners insurance, lender guidelines, and other debts can change both the payment and qualifying income substantially. Closing costs and reserves are additional to the down payments shown.
If those income estimates feel out of reach, look at more than one price point and loan structure. A second qualified borrower may change the picture, while HOA dues or other debts may reduce what you can comfortably spend. I want you to understand the total monthly cost before you fall in love with a home.
First-time buyer assistance to ask about
CalHFA MyHome. This deferred-payment junior loan can help eligible first-time buyers with down payment or closing costs. The maximum is generally up to 3.5% with a CalHFA government loan or 3% with a CalHFA conventional loan, subject to program rules. CalHFA requires homebuyer education. Its 2026 standard government and conventional income limit for San Mateo County is $256,000; Dream For All has a separate limit. Check current eligibility with a CalHFA-approved lender.
County and city resources. San Mateo County lists ownership assistance resources, including local opportunities and information about its Reissued Mortgage Credit Certificate program. Availability and eligibility vary. An older county page also references HEART’s buyer loan, but HEART says that loan has not been offered since January 28, 2026.
California Dream For All. This shared-appreciation program has a separate income limit and a limited application window. The 2026 application portal closed March 16; watch CalHFA for a future opening rather than counting on it for a purchase today.
Get pre-approved before choosing your price range
A pre-approval conversation helps you compare FHA, conventional, jumbo, and assistance options with your actual income, debts, and savings. Ask the lender to show the estimated monthly payment, cash needed at closing, and funds you would still have afterward. A pre-approval is subject to underwriting and property review, but it is a much stronger starting point than an online calculator.
I often introduce buyers to Spiro Hishmeh at C2 Financial because he takes time to explain the tradeoffs in plain language. You are free to choose any lender, and I encourage you to compare loan estimates.
Quick questions buyers ask me
Can I buy in San Mateo County with less than 20% down?
Yes, if you qualify for an appropriate loan and the full payment fits your budget. Many loan programs permit less than 20% down; mortgage insurance or other program costs may apply.
Do I need to earn more than $300,000?
Not for every home. The $850,000 examples above illustrate lower income thresholds under one set of assumptions. The right answer depends on your income, debts, available cash, loan, and the property’s total costs.
Should I wait for mortgage rates to drop?
No one can reliably time rates or home prices. Compare today’s payment with a budget you can sustain. Refinancing may be possible later if conditions and your qualifications allow, but it should not be the reason the purchase works.
Let’s build your plan
Start with a lender conversation through Spiro at C2 Financial or a lender of your choice. Then I can help you compare neighborhoods, homes, and the complete cost of ownership, with no pressure.
Talk with John